Beginner Needs Help

I am using the following things:
Windows 10 Laptop
Native-Instruments Komplete 10
Sonar X2
Focusrite 2i2 USB Audio Interface
m-Audio Axiom 49 Controller
Casio Privia 88-key piano with USB Midi
Mackie SRM 150 Active PA Speaker connected to the Focusrite as a monitor.
 
I have an MP3 file imported as track 1 in Sonar X2.  I would like to be able to insert a second track where I would be able to choose an instrument within the Native Instruments Kontakt program, in order to be able to play along with the track 1 audio, to eventually record the midi data that I am playing from each of the two keyboard playing surfaces, so to speak.  Ideally, I would want to assign the 88-note board to one of the tracks in Sonar, and the Axiom 49-note controller to another track, each with their own instrument from Native Instruments Kontakt.  I want to hear myself playing along with the audio track through the speaker I have connected to the audio interface.
 
How do I accomplish this?

Thanks for the reply.  I will review those links.  I manged to get things working.  I had to remove the VST folder for Native Instruments from within Sonar, to then re-add the folder, and reboot the laptop, in order for the Kontakt option to begin working properly to add a synth as a simple instrument track.
 
One thing I am noticing is that I can't play two keyboard controllers at the same time if each of them are assigned to different USB ports, unless I am doing something incorrectly.  I can only play whichever instrument track I have selected.  I would like to be able to play both controllers simultaneously if possible.  I wonder what would happen if I load two instruments onto the Kontakt rack while using only a single track in Sonar?